Chen Ning Yang is a Nobel laureate in physics who, together with his colleague Tsung-Dao Lee, proposed a theoretical framework for the violation of parity conservation in weak interactions. This work earned them the Nobel Prize in Physics in 1957.

As for the notion of "practicing upmanship" and using "taste to choose research directions," these are somewhat subjective concepts that could be interpreted in a few different ways. One possible interpretation is that Yang believes in striving to do the best possible work in his field, and in choosing research directions based on his personal interests and preferences rather than solely on practical considerations such as funding or potential impact.

This approach to research is not uncommon among scientists, who often pursue areas of study that they find personally fulfilling or intellectually stimulating, even if those areas may not immediately appear to have practical applications or commercial value. In some cases, this type of research can lead to breakthrough discoveries that have far-reaching implications for society, even if those implications were not immediately obvious at the outset.

Overall, it seems that Yang's approach to research involves a combination of rigorous scientific inquiry and a willingness to pursue lines of inquiry that may not be immediately lucrative or popular, but that have the potential to yield important insights and discoveries.